Method of and apparatus for tempering glass sheets



H. LEBEL 1,895,548

METHOD OF AND APPARATUS FOR TEMPERING GLASS SHEETS Jan. 31, 1933.

Filed July 22, 1930 gwuvntcw Henry Lebe Z X of apertures B-1 located at selected points Patented Jan. 31, 1933 ITED STATE EELE'tY LEBEL, 0F PARIS, FBMICE, ASSIGNUE I0 SOCIETE ANONYM'E DES MANU- FACTURES DES GLACES z PROD'UI'I'S CHIMIQUES DE SAINT GOBAIN, (GHAUNY &

GREY, GE PARIS, FRANCE METH'UD 6F AND APPARATUS E012. TEMPERHTG GLASfi .llpplication filed July 22, 1930, Serial No. 469,745, and in France August 8, 19%.

It has been proposed to use a windshield for automobiles so tempered as to produce strain therein at selected points, whereby a selected and desired breaking pattern may be obtained, and it has been further proposed to use air jets directed on selected points on the heated sheet as a means of accomplishing the desired tempering. According to the present invention I propose to accomplish the desired tempering by radiation from the heated sheet onto a cooled metallic surface placed in proximity (preferably only at selected points) 9 to the surface of the sheet, but not contacting therewith to thus avoid defacing the surface of the sheet.

F or the purposes stated, my invention comprises both the method of tempering the sheet and an apparatus for carrying out such method as will be hereinafter described and claimed.

Referring to the accompanyin drawing in which corresponding parts are esignateoi by corresponding marks of reference,-

Fig. 1 is aside elevation partly in section of an apparatus embodying my invention' and adapted to carry out the process here described.

Figs. 2 and 3 are details of with the apparatus shown in A is a sheet of glass which has been uniformly heated to a temperature corresponding to that of the commencement of its softening, which for ordinary window glass will be in the neighborhood of 550 to 620 C. The sheet in this highly heated condition is placed between two cooled surfaces, but out of contact therewith. Under these conditions the surfaces of the sheet will lose heat by radiation to the cooled surface and this without impairing the finish of the glass surface. Each cooled surface is, by preference, one side of a suitable hollow box B, provided with induction and eduction pipes F and G, by

parts to be used which a cooling medium may be circulated through the box to remove the heat absorb-' ing from the plate.

In order to locally chill the surface of the plate at desired points the face of the box adjacent the sheet has formed therein a series and threaded to receive hollow bosses C projecting beyond the general level of the sur face of the box. The tops of the bosses are thus brought into close proximity with the surface of the sheet whereby the selected chilling will be obtained. When it is desired to suppress the chilling adjacent to any boss, that boss may be removed and replaced by a filling plug E, not projecting so far from the surface of the cooled plate. lln this way a selected chilling pattern may be obtained on the surface of the sheet; and hence the character of its burst determined.

Having thus described my invention what I claim as new and desire to secure by United States Letters Patent is 1. The hereinbefore described method of tempering glass sheets which comprises uniformly heating the sheet to a temperature close to its softening point and similarly chilling the opposite surfaces of the sheet while soheated by brin 'ng such surfaces simultaneously into proximity to but out of contact with cool surfaces.

2." The hereinbefore described method of tempering glass sheets which comprises uniformly heatin the sheet to a tem erature close to its sof tening point and chiing the selected points on the surface of the sheet by bringing the same into roximity to but out of contact with cool sur aces.

' 3. In an ap aratus for tempering glass sheets, the com ination with oppositel disposed plates havin bosses therein at so acted signature. a V

HENRY LEBEL. 

